<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <!-- 写 JS 的方式二： 行内式； （但这种写法被 ！！禁止！！） -->
  <A href="jAvascript: console.log('xxx', 'aaa');">xx</A>
  <H1>YO！</H1>
</body>
</html>
<script>
// 代码块  - block
{
  var num = 123;
  var num2 = 456;
  console.log(num, num2)
}
</script>